diff --git a/paddle_quantum/circuit.py b/paddle_quantum/circuit.py
index dc4e8b96688cf917f968664160093cf21551b415..2eba39f84a900b6294c97dc01585ec2e47ebadae 100644
--- a/paddle_quantum/circuit.py
+++ b/paddle_quantum/circuit.py
@@ -59,15 +59,6 @@ class UAnsatz:
                         paddle.to_tensor(np.array([math.pi / 4])), paddle.to_tensor(np.array([-math.pi / 4]))]
         # Record history of adding gates to the circuit
         self.__history = []
-        
-    def expand(self,new_n):
-        """
-        为原来的量子电路进行比特数扩展
-
-        Args：
-            new_n(int):扩展后的量子比特数
-        """
-        self.n = new_n
 
     def __add__(self, cir):
         r"""重载加法 ‘+’ 运算符，用于拼接两个维度相同的电路